Method and apparatus for purging headspaces of filled cans



Dec. 8, 1970 c. E. JANTZE ETA!- 3,545,150

I ,METHOD AND APPARATUS FOR PURGING HEADSPACES OF FILLED CANS 5Sheets-Sheet 1 Filed Dec. .5, 1968 INVENTORS CLYDE E. JANTZE EDWARD A.ARNOTT EARLE v scorr BY/{mi/ f ATT'Y Dec. 8, '1970 c. E. JANTZE ETAL3,545,150

METHOD AND APPARATUS FOR PURGING HEADSPACES OF FILLED CANS 5Sheets-Sheet Filed Dec.

INVENTORS CLYDE E. JANTZE EDWARD A. ARNOTT EARLE v scorr BY "Z, v

w %T X Dec. 8, 1970 c. E. JANTZE EI'AL 3,545,160

METHOD AND APPARATUS FOR PURGING HEADSPACES OF FILLED CANS 5Sheets-Sheet 4 Filed Dec.

Dec. 8, 1970 c. E. JANTZE ETAL 3,545,160

METHOD AND APPARATUS FOR PURGING HEADSPACES OF FILLED CANS Filed Dec. 5,1968 5 Sheets-Sheet 5 INVEN TORS CLYDE E. JANTZE EDWARD A. ARNOTT EARLEMSCOTT ATT'Y.

United States Patent 3,545,160 METHOD AND APPARATUS FOR PURGINGHEADSPACES OF FILLED CANS Clyde E. Jantze, Riverside, Edward A. Arnott,Blue Island, and Earle V. Scott, La Grange Highlands, Ill., assignors toContinental Can Company, Inc., New York, N.Y., a corporation of New YorkFiled Dec. 5, 1968, Ser. No. 781,426 Int. Cl. B65b 31/02 U.S. Cl. 53-7Claims ABSTRACT OF THE DISCLOSURE A can intake arrangement and gassingnozzle to purge air from the headspaces of filled cans as they approachchucking position on the seaming turret. The body infeed conveyor,infeed turret and seaming table are positioned for maximum effectivegassing travel. A slot along the end feed guide delivers a gas jet whichsweeps under the flanges of ends approaching the infeed position. A gasnozzle adjacent the infeed turret pocket delivers inert gas into thepocket through two banks of ports partially surrounding the pocket. Onebank along the upper face of the nozzle case directs gas jets to sweepthe headspace, while gas jets from a lower bank sweep under the bodyflange. A by-pass slot between the port banks diverts a portion of theflow in a fan jet, to preclude induction of air into blind spacesbetween ports.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to can filling and closing methods and apparatus, and moreparticularly to that portion of the operation involved with intake tothe closing machine and purging treatment of the cans and covers orends, preparatory to the closing and seaming operation. The turret-typeclosing machines described in Kronquest et al., U.S. Pat. No. 2,255,707,issued Sept. 9, 1941, and Laxo, U.S. Pat. No. 2,540,001, issued Jan. 30,1951, are representative of closing machines for use with which theinvention is particularly well suited, although not limited thereto.

The prior art Handling and closing conditions generally preclude fillingbeverage cans to the lip. In order to minimize spillage, it is necessarythat some headspace remain after the fill. The headspace is thenpreferably purged and inerted before sealing, particularly in the caseof such beverages as beer, which may deteriorate rapidly, in thepresence of air. Without purging, a significant volume of air willremain in the headspace after closing and seaming.

A convenient and economical method of purging the headspace is referredto in the trade as undercover gassing, wherein an inert gas is directedinto or across the headspace below the cover or end to force or induceair from the space, in order to establish and maintain an inertatmosphere in the headspace just before and up to the time at which theend is chucked to the body.

Generally, gassing of filled cans has been performed by means of gassingnozzles on the infeed turret directing a gas stream through the spacebetween the end and the container. This arrangement has been fairlysatisfactory at low production rates, but prior designs have notperformed acceptably at high production rates, for two principalreasons. First, prior nozzles do not provide fully effective gas-flowpatterns, in that an excessive amount of air outside the headspace isinduced with the gas stream reducing efficiency. Consequently, asubstantial quantity of air is trapped in the headspace with theresidual gas,

'ice

when the can is closed. Second, with the arrangement of apparatusheretofore employed, the period during which the end is in 'sufficientproximity to the can prior to closing is too short for a full scavengeof the headspace at any practicably achievable gassing rate andefficiency. Tests with prior methods and apparatus have shown thatearlier initiation of gassing merely wastes the gas. Prolongation of thegassing stage along the seaming table is impractical by reason ofaggravated spillage hazard, together with high cost and complexity ofthe equipment. In any event, gassing on the seaming table is undesirableby virtue of reduction in available seaming travel, which should bemaintained at maximum value, if high quality seaming is to be performedat high production rates.

SUMMARY OF THE INVENTION An object of this invention is to provide, inassociation with a can filling and closing line, an improved method andapparatus for undercover gassing of filled cans approaching the closingand seaming operation.

Another object of this invention is to provide a gassing arrangement inassociation with an infeed turret, whereby to purge the headspace of afilled can with maximum efiectiveness under conditions of short gassingexposure.

Yet another object of this invention is to provide an undercover gassingmethod and apparatus which precludes or minimizes excessive airentrainment or induction into the gas stream.

A still further object of this invention is to provide a gassingarrangement of a design which best assures effective distribution andproportioning of gas to the gassing areas and thorough scavenging of airfrom the undercover and head spaces.

The foregoing objects are achieved by a novel method of gassing,implemented by a novel arrangement and structure of the gassingapparatus. With a particular positioning of the infeed conveyor, infeedturret and seaming table, the can and its end are brought into positionfor initiation of gassing at a point optimally in advance of chuckingposition, providing maximum effective gassing travel before the end ischucked to the body. A slot over the nozzles, along the end guide rail,sweeps under the end flange. The nozzle ports are arranged in dualbanks, one above the other, with the upper, primary bank sweeping theheadspace. The lower, secondary bank sweeps under the body flange,minimizing entrainment of air from beneath the flange. The end carriedimmediately above the body acts as an upper shield.

In association with the dual bank arrangement, the nozzles and manifoldsare proportioned for optimum gas quantity and distribution, to insurethorough purging of the headspace in the gassing time provided. Aportion of the gas flows through a slot between nozzle banks to by-passthe ports and to preclude air induction through dead spaces betweenports.

The foregoing and other objects, advantages, and details of theinvention will be best understood from the following description read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic and diagrammaticplan of infeed apparatus associated with a turret-type closing machine,arranged according to this invention;

FIG. 2 is a partial, diagrammatic plan, similar to FIG. 1, showing canand end infeed relationships on a larger scale;

FIG. 3 is a plan view of the infeed turret represented in FIG. 1, withdistributor and valve assembly removed to expose principal parts of thenozzle assembly;

FIG. 4 is an end elevation of the one nozzle sector taken on line 44 ofFIG. 3, showing ports arranged according to this invention;

FIG. 5 is a horizontal section through a nozzle sector taken on line 55of FIG. 4;

FIG. 6 is a horizontal section through a nozzle sector taken on line 66of FIG. 4;

FIG. 7 is a vertical radial section through a nozzle sector, taken online 77 of FIG. 4;

FIG. 8 is a fragmentary plan view of the end feed guide and can feedturret adjacent to the seaming table, with portions broken away to showthe upper gassing slot;

FIG. 9 is a partial vertical section on line 99 of FIG. 8, showing theinlet and passage to the upper gassing slot;

FIG. 10 is a radial section through the infeed turret taken on line 1010of FIG. 3, showing a can body and cover in position upon transfer fromthe infeed conveyor to the seaming turret during gassing, just prior toclos- FIG. 11 is a schematic sectional view, similar to FIG. 10, showinggas flow patterns through the nozzle, at approach and across the canheadspace; and

FIG. 12 is a schematic perspective along the top of a can, showing gasflow patterns across the headspace.

DESCRIPTION OF PREFERRED EMBODIMENT The invention here shown anddescribed is designed for use in conjunction with a turret-type closingmachine, which performs the function of seaming the ends to the filledcan bodies. The infeed to the closing machine involves bringing togetherthe filled can, delivered from the filling machine along a conveyor, andthe cover or end, delivered from a hopper or stack, fed in synchronismwith the can feed conveyor. In order to be effective, the gassing mustbe performed in the interval between the point at which the end isbrought over the top of the can, in proximity thereto, and the point atwhich the end and the can flange are mated for chucking, preparatory toseaming.

Since it is desirable to devote as much of the can travel on the seamingtable as possible to the seaming operation, the can and its end shouldbe delivered to initial gassing position as far in advance of theseamed-can discharge point as possible. Gassing preferably is providedjust before can and end reach chucking position on the seaming table. Ifthen the gassing effectiveness is also enhanced, the combination ofthese measures greatly facilitates the operation of the closing machineat a high production rate, without a sacrifice in the quality andintegrity of the finished product.

Referring now to the plan of FIG. 1, cans C are shown traveling fromleft to right along an infeed conveyor line 10 toward the closingmachine turret 11. At the same time, ends E are fed from stacks 12 by anend feed turret 13 along guide 14, passing over and along infeed turrettoward conveyor line 10 and closing machine turret 11. The can and endfeeds are synchronized so that a can C and an end B arrive together atturret 11. Such feed apparatus is well known in the art, not formingpart of this invention, and the apparatus need not be described here indetail.

As end guide 14 and can conveyor line 10 converge near closing machine11, each end B passes across and above an incoming tangent point T onchuck circle 11a, along the projection of conveyor line 10.

Experience has shown that undercover gassing cannot effectively beginuntil the can and end centers are quite near to coincidence. Otherwise,much of the effect is wasted outside the headspace, and excessivedilution by air induction results. It has been found that with arepresentative beer can size, the end and can eccentricity should notexceed about /2 inch when gassing is initiated. The position along theperiphery of the infeed turret 15 at which a given value of S willobtain can theoretically be predetermined within limits by institutingappropriate departures in the paths of cans along line 10, ends alongguide 14 or both upon approach to seaming turret 11. However, inertialeffects at high speeds predicated for high production rate precludesubstantial departures from true linear and rotary motions indicated,particularly with respect to jostling and sloshing effects on the cans,aberrations in alignment and juxtaposition at the desired conjunctionpoint T. Reasons of manufacturing economy in the turrets, guides andrelated parts of the apparatus, particularly in feeding devices, alsodictate against resorting to expedients involving substantial divergencefrom uniform feed courses just before closing.

Establishment of the desired gassing relationship for the earliestfeasible can capture position at feed turret 15, and relative to seamingturret 11, is achieved by so positioning axes of turrets 11 and 15 thatthe respective centers 11a and 15a are angularly displaced from a lineXX at right angles to can feed line 10 through point T, with chuckcircle 11b and end feed circle 15b tangent at T. Thus, line YY throughcenters 11a and 15a lies at an angle A relative to line XX, the centersbeing swung about point T in the direction to bring center 15a towardline 10 at the infeed side of point T, that is, clockwise in thearrangement of FIG. 1.

The beneficial result of the positioning described is best understood byreference to FIG. 2. The broken arc represents end feed along circle 15btoward point T in the direction of the arrow, with the feed radiuscentered on line XX. Line XX passes through point T in the direction ofthe arrow. In that case, ends pass through a point S at a distance Sfrom can feed line 10, corresponding to the maximum can and endseparation at which gassing may be effectively initiated. S -Trepresents the effective gassing travel. The end feed circle 15b iscentered on line YY, at angle A to line XX. In this case, the center ofend E passes through a point S at a distance S from line 10,corresponding to separation S, at a distance S T from point T,substantially longer than travel S T.

As seen in FIG. 1, the provision of full gassing travel in advance ofcompleted intake at T affords maximum practicable travel on turret 11 todischarge point D, at tangency with the discharge turret 16,substantially 270 are, devoted to chucking, spin acceleration, seamingand release to discharge. In consideration of apparatus spacerequirements, 270 seaming turret travel is substantially the maximumpracticably obtainable. Experience has shown that it is desirable andnecessary to devote such travel as fully as possible to the seamingoperation, particularly at high production rates and correspondinglyhigh linear can speeds. k

In order to realize rates on the order of 1000 can per minute andupward, extremely high gassing effectiveness is requisite. Thisinvention achieves such effectiveness by virtue of a novel gassingpattern, nozzle and associated apparatus. A top plan view of theapparatus is shown in FIG. 3. Nozzle sectors 17 encircle and rotate withturret shaft 20 about a vertical axis. The number of sectors 17 isdetermined according to the velocity and spacing of cans arriving at theinfeed turret 15 along conveyor line 10 (FIG. 1). An arcuate wall 21defines a can pocket P, sized to accommodate the largest can diameter ofa limited range with which a given assembly is to be used.

For best results, the turret size and number of sectors 17 are selectedfor spacing P -P as nearly as possible the same as the can infeedspacing along conveyor line 10, thus obviating or minimizing intakeacceleration or deceleration. For manufacturing convenience and economyin detail finishing, the nozzle sectors 17 are best made by casting orfabricating a complete ring, finishing the continuous cylindrical andplanar surfaces, drilling bolt-holes 22, and then sawing along radiallines 23 through holes 22, midway between pockets P. However, acontinuous ring may be used, if preferred, in which case holes 22 may beof such number and location as necessary for clamping the ringcomprising nozzles 17 on the turret 15.

The design of the nozzle 17 is conducive to exceptionally high gassingeflectiveness. Details of nozzle 17 are best seen in FIGS. 4 to 7inclusive. Referring first to FIG. 4, a series of ports 23 constituteprimary gassing ports, ranged near the upper face 24 of nozzle 17. Asecondary series of ports 25, smaller than primary ports 23, constitutea second bank in a plane parallel to the plane of ports 23, near thelower face 26 of nozzle 17. As best seen in FIGS. and 6, all of ports23- and 25 communicate with the manifold chamber 27. The primary ports23 are arranged along an arcuate wall 28. The secondary ports 25 arearranged along an arcuate wall 29, forward of wall 28.

Referring now to FIG. 7, inner wall 28 depends from the top of nozzle17, transecting the upper portion of chamber 27. Outer wall 29 extendsupward from lower face 26, transecting the lower portion of chamber 27,partially overlapping wall 28. Thus, walls 28 and 29 define an arcuatepassage 30, communicating with chamber 27, and leading to an arcuatespace 31, opposite ports 23. A pair of struts 32 serve as bracing, asbest seen in FIGS. 4 and 5. A central group of ports 23 face space 31between struts 32, while left and right groups face spaces 31a and 31b,outwardly of struts 32, so that struts 32 do not present a flowobstruction.

FIGS. 8 and 9 show the provisions for gassing under the cover flange.Ends approach gassing position along the guide rails 18 and 19, whichdefine the path 14 between them. Rail 18 overlies the can feed turret 15and is concentric therewith, as best seen in FIG. 1. Rail 18 liesbetween cover plate 60 and the top plane of nozzles 17 passingunderneath. Rail 18 is provided with a long arcuate slot 61 concentricwith and radially inward of the cover flange rail 18a. At its approachend, slot 61 communicates with port 62 in cover plate 60, which isconnected by line 63 to the CO source (not shown). Except at port 62,the upward opening of slot 61 is closed by the overlying rail member 18which is clamped to cover plate 60 by any suitable means (not shown).Running clearance between the bottom face 24 of rail 18 and the top face64 of nozzle 17 constitute the shallow slot 65, opposing the flange E ofan end E carried on the rail 18a. Slot 65 is in communication with theCO supply line 63 through the arcuate slot 61. Gas, supplied throughpipe 63, floods the slot 61 and then fans out in a high velocity jetthrough the slot 65, as best seen in FIG. 8, flooding and enveloping theend flanges E (FIG. 8), as the ends E move along the rail 18a towardsuperposition over corresponding can bodies approaching on the can feedline. The gas flood zone extends from the position at which each end Ebegins lapping can C to a primary gassing zone, where end E is nearlysuperposed over a can C. The pocket defined by flange E is purged of airprior to and until the purge effected by gas from nozzle 17, minimizingthe entrapment of air around the flange E and possible subsequententrapment in the headspace as the end B is lowered onto the can C,preparatory to seaming.

For the reasons above given in the description associated with FIGS. 1and 2, the arrangement there shown of the turrets and feeds for earlyjuxtaposition of cans and ends substantially enhances the total gassingeffectiveness including that ascribed to the end flange purging shown inFIGS. 8 and 9.

The manner in which the ports are arranged for gassing operation is bestunderstood from consideration of FIG. 10, which shows the gassingassembly and its relation to the infeed turret 15, the seaming turret11, the can body C, the end E, and the other apparatus associated withunder-cover gassing at intake to the seaming turret 11. In this view,the relationship of the various elements is represented with can C andend E superimposed just before releasing end E from the rails 18 and 19of guide 14. That is, the can and end are here shown in the positionsreached substantially at point T, FIG. 1. Pusher 33, stop 34, and infeedmold 21, serve to position can C on support chuck 35, carried by seamingtable 36. Hub 37, aflixed to shaft 20, carries the gassing assembly,comprising clamping ring 38, mold ring 39, spacer ring 40, nozzles 17,and wear ring 41, for rotation relative to the distributor assemblyconsisting of face valve 42, gasket 43, and cap 44. The several parts ofthe gassing assembly are held together and clamped to the hub 37 bymeans of several series of bolts or cap screws (not shown) provisionbeing made therefor in the uppermost parts by series of holes or taps22, 45, 46, and 47 (FIG. 3), it being understood that the intermediateand lower parts of the assembly are provided with matching taps or holesas required. The arrangement is designed to facilitateinterchangeability of the several parts with corresponding partsrequired to accommodate cans of different diameters, or other infeedspacings with which the basic turret assembly is to be used. The nozzles17 may be removed and a blind ring substituted, for use of the turretwith can lines not requiring gassing.

As best seen in FIG. 3, wear ring 41 is provided with a series of sectorports 48, equal in number to the number of nozzles 17, centered aboutradii common with the center radii of nozzles 17. Referring again toFIG. 10, wear ring 41 rides in contact with valve member 42 alonginterface 49. Valve member 42 has a single port 50, whose shape and sizeare the same as those of ports 48, valve member 42 being so positionedthat, as each rotating nozzle 17 traverses its gassing arc,corresponding port 48 sweeps across port 50, being in full registrysubstantially at the position of FIG. 10.

Port 48 communicates with chamber 27 in nozzle 17 through connectingducts 51 and 52, in spacer 40 and ring 39, respectively.

OPERATION As seen in FIG. 10, nozzle 17 is positioned opposite can C andend B with ports 23 facing the space under end E and over the top of canC, ports 25 being directed toward can C just below body flange F. Inertgas, such as CO for example, is supplied to distributor 44 from anysuitable source. In a brewery, CO is regularly available from plantsupply lines, which may be tapped and connected to distributor 44through regulators and control valves (not shown) in any well knownmanner to supply distributor 44 whenever the can-closing line is inoperation.

With a given nozzle 17 in the gassing position of FIG. 10, gas flowsfrom distributor 44 through valve port 50, sector port 48, and ducts 51,52 to manifold chamber 27, from which the gas is delivered through theprimary ports 23, secondary ports 25, and arcuate passage 30. As bestseen in FIG. 5, ports 23 and 25 are arranged along concentric arcsdefining fan perimeters.

The gassing pattern is illustrated by FIGS. 11 and 12, which showschematically the movement of gas, indicated by filled arrows, andscavenged air, indicated by open arrows. Referring first to FIG. 11,ports 23 constitute flow paths from chamber 27 directly into dischargespace 31 and thence toward the space between end B and can C, across theheadspace H above the liquid fill level L. A smaller volume flowsthrough ports 25, the total area of which is substantially less thanthat of ports 23. A substantial volume flows through the relativelylarge bypass 30, aided by the inductive effect of the jets from ports 23flowing across the opening of by-pass 30 into space 31. Thus, gas leavesthe chamber 27 in three stream layers, the two upper streams, propagatedfrom ports 23 and bypass 30, reuniting in principal part as aconsolidated stream along flange F at the periphery of headspace H,thence flowing across the headspace, under the principal directional andinductive effects of the jets from ports 23.

Gas jets from ports 25 impinge on can-wall surface W in a plane a shortdistance below flange F. The stream so generated flows around and alongsurface W in both directions from the plane of the view, sweeping thespace defined by nozzle wall 29 and surface W, in a direction generallytransverse to can C. Impingement of the highvelocity jets on the surfaceW diverts a portion of the secondary stream to sweep along the undersideof flange F and a portion to flow generally downward along surface W.The downward diversion precludes induction of air from space below upperwall surface W, that is, from below the plane of ports 25.

The total area of ports 23 and by-pass passage 30 is proportioned to thetotal area of ports 25 approximately as the ratio of the volumes to beswept by the primary and secondary streams respectively. Withproportionate adjustment for the effect of diversions and other flowconditions, the respective stream velocities transversely of can C willbe substantially the same and there will be no significant tendency tocross-flow between the primary and secondary streams through the narrowpassage between flange F and Wall 29.

Now referring particularly to FIG. 12, the central group of primaryports 23a are parallel, establishing a central gas stream across themid-zone over the top of can C. The boundary groups 23b and 230, on axesradially of the can C, establish converging streams flowing in towardthe boundary segments of the headspace, being then in part deflected byimpingement upon the central stream, to flow generally paralleltherewith across the boundary segments. The primary flow thus sweeps theentire headspace with minimal wasteful marginal flow outside the can lipbeyond the headspace at its cross-stream diameter. The full sweep thusestablished minimizes induction of air into boundary spaces upstream andlaterally of the headspace, thus insuring maximum eflectiveness inentraining and purging air from the headspace. At the same time, thefull-fan stream from the by-pass 30 supplements the primary flow andsubstantially precludes induction of air through up stream spacesbetween the jets issuing from the primary ports 23, particularly thespaces between groups 23a and 23b, and between 23a and 230.

The timing of the gassing stage is such that gassing begins just beforethe end/can position of FIG. 2 and continues at least until the end B ischucked to can C, the gassing intensity being maintained at suificientvalue to preclude air infiltration at gas cut-off. The timing isdetermined by appropriate sizing of the inlet ports 48 and valve port50, for any given number of nozzles 17. In the example shown anddescribed, with 12 nozzles at 30, inlet ports 49 and the valve port 50each have an arcuate span of 19, providing 38 gassing travel of eachnozzle from cracking to cut-01f. Thus, while there is necessarily somevolume fluctuation with change in total inlet port area as each inletport passes the valve port, there is never a no-flow condition throughthe valve port, since any given inlet port is in communication beforeits predecessor is cut oil. The adverse elfects of extreme throttlingand surging flow are avoided, while maintaining maximum effecitve flowto each nozzle without excessive wastage. The fixed valve port 50 (FIG.8) is positioned to center on a radius about midway between turret radiithrough points S and T (FIG. 2), so that the peak gas flow obtainsduring the gassing travel of each nozzle between S and T.

Since the nozzle ports may become contaminated, crusted or plugged, asby spillage from cans, occasional cleaning or sterilization may berequired. This servicing is readily performed by connecting the turretand manifold assembly to a hot water or steam line, with switchovercontrol, whereby from time to time the ports can be scoured and flushedby running the turret with hot water or steam fed through the gassingsystem. Such oc casional cleaning can be scheduled with other:maintenance operations, minimizing down-time.

It will be understood that the particular proportioning and arrangementof parts shown is by way of example only. The example used forillustrative vpurposes is that of a machine designed and constructed tohandle standard twelve-ounce beer cans, delivered to the closing machineat a rate on the order of 1000 cans per minute and upward, spaced about3 /2 inches. For this requirement, best results are achieved inaccordance with this invention by use of a twelve-pocket turret. Thenozzle 17 for each pocket, as illustrated in FIGS. 4 to 6 inclusive, has13 /8 inch primary ports 23 grouped 3-7-3 along a arc of about 1% inchradius, 11% inch diameter secondary ports 25 equally spaced along a arcof about 1 /2 inch radius, and by-pass 30 about A inch wide.

It will also be apparent that application of the invention is notlimited to round, metal cans, the invention being readily adaptable foruse in methods and apparatus associated with hermetically closing orcapping jars, bottles and other filled containers of various shapes andsizes. Manifestly, steam, nitrogen or other gas may be used for purging,according to the residual headspace atmosphere best suited to theparticular product fill involved.

Those skilled in the art will be able to devise other arrangements,proportions and dimensions of the parts, and other variations andmodifications for operating conditions other than the exemplary oneshere given by way of illustration, without departing from the spirit andscope of the invention, as defined in the appended claims.

What we claim is:

1. Apparatus for a can closing line comprising: a closing turret; a caninfeed turret concentrically carrying undercover gassing nozzles; anarcuate end feed guide concentric with said infeed turret; a linearinfeed conveyor for delivering a succession of filled cans to saidclosing turret, said conveyor and said guide being arranged to delivercans and ends respectively to a point of concentric superimposition uponsaid closing turret, said point being on a line diametric of both saidturrets, the apparatus being further characterized in that saiddiametric line is inclined to a line through said point perpendicular tosaid conveyor line, with the center of saidinfeed turret at that side ofsaid perpendicular line from which cans approach said point along saidconveyor line; and inertgas jet means associated with said can infeedturret, including first means adapted to direct some of said gas againstthe flanges of covers approaching said point along said guide, secondmeans adapted to direct some of said gas between said end and said canwhen said end is superimposed over said can, and third means adapted foractivation simultaneously with said second menas to direct some of saidgas against said cans along and under the lips of said cans; wherebysubstantially to preclude trapping of air in headspaces of said canswhen said cans and ends are seamed on said closing turret.

2. A nozzle assembly for gassing a filled can having a flanged endpositioned closely above the can lip, preparatory to closing,comprising: a shallow housing having a chamber bounded by side walls; anouter wall adapted partially to surround a can, said outer wallextending between said side walls along the bottom of said chamber to aright less than the depth of said chamber; an inner wall substantiallyequidistant from said outer wall, said inner Wall extending between saidside walls along the top of said chamber to a depth less than the depthof said chamber, defining a passage along said bottom leading from saidchamber to said outer wall; a bank of first ports in said inner wallcommunicating with said chamber; a bank of second ports in said outerwall communicating with said passage; and a plate above said housing,spaced therefrom, the clearance between said plate and said housingconstituting a slot communicating with atmosphere above said ports;whereby, upon opposing said nozzle assembly to said can with said outerwall below said lip, and therewith supplying gas to said chamber andsaid slot under pressure, gas from said slot sweeps the flange of saidend, gas from said first ports sweeps the head space between said endand said can, while gas from said second ports sweeps the wall of saidcan below said lip.

3. A nozzle assembly according to claim 2, wherein the planconfiguration of said housing is generally that of an annulus sector,whereby a plurality of said housings may be abutted in series toconstitute an annular nozzle ring adapted for carriage upon a turret.

4. A nozzle assembly according to claim 2, wherein said passage is afirst passage, said inner, outer and side walls defining a secondpassage communicating with said first passage, said second passageterminating in an uninterrupted opening forward of said inner wall,whereby, upon so opposing said nozzle and so supplying said gas, anundivided stream of gas from said second passage merges with gas fromsaid first ports to constitute an undivided gas stream flowing towardsaid headspace.

5. Apparatus for gassing headspaces of a series of filled cans receivedby said apparatus, comprising: a rotatable can feed turret; end guidemeans associated with said turret defining a channel concentric withsaid turret for guiding a flanged end into close superposition over eachcan of said series, as said can is received by said apparatus; a pocketmember carried by said turret, said pocket member having a plurality ofpockets adapted successively to receive can of said series with the lipof each said can upward of a corresponding pocket; a plurality ofnozzles constituting a ring carried by said turret above said pocketmember, there being a nozzle aligned with each said pocket; an elongatedslot opening into said channel in a plane upward of said nozzles, alongsaid guide means; a first discharge bank in said nozzle positioned tooppose the space between said can and a superposed end, upon receptionof a can in a corresponding one of said pockets; a second discharge bankin said nozzle positioned to oppose the upper wall portion of saidpocketed can; a manifold communicating with said discharge banks; andmeans for supplying gas under pressure to each of said slot and saidmanifold separately, whereby said apparatus is adapted to cause gas fromsaid slot to sweep the flange of an end approaching said one pocket andindependently thereof to cause gas from said first bank to sweep saidspace, while gas from said second bank sweeps said can wall portion.

6. Apparatus according to claim 5, wherein said nozzle includes sidewalls bounding said manifold; an arcuate outer wall extending upwardbetween said side walls from the bottom of said manifold to a planebelow the plane of said first bank, said outer wall being concentricwith said pocket; an arcuate inner wall extending downward between saidside walls from the top of said manifold to a plane above the plane ofsaid second bank, said inner wall being concentric with said outer walland more remote from said pocket than said outer wall; first ports insaid inner wall constituting said first bank; said second ports in saidouter wall constituting said second bank; said outer wall and said sidewalls defining a discharge chamber for said first bank, said inner walland said side walls defining an inlet passage communicating between themanifold chamber and said second bank, said outer wall and said innerwall with said side walls defining an uninterrupted by-passcommunicating between said inlet passage and said discharge chamber;whereby to propagate a first stream from said first ports, a secondstream from said second ports, and an uninterrupted by-pass streammerging with said first stream upstream of said space, to

10 constitute an uninterrupted primary stream substantially precludinginduction of air into said space between jets propagating said firststream, while said second stream substantially precludes induction ofair from below said lip into said primary stream.

7. A method of purging air from space between the contents of acontainer and a flanged cover being carried over the mouth of saidcontainer, preparatory to sealing said cover to said container along thelip thereof, comprising: directing a substantially undivided first gasstream immediately under and across said cover and along the flangethereof; propagating a series of gas jets along a line laterally remotefrom said space, thereby constituting an initially divided second gasstream, and directing said second stream toward and across said spacegenerally transversely of said container; directing a third gas streamagainst the outer wall surface of said container generally transverselythereof immediately below said lip; and, simultaneously with thepropagation of said second stream, directing a substantially undividedfourth gas stream into said second stream substantially throughout itstransverse extent and between said line and said space, all said streamsbeing directed in the same general direction transversely of saidcontainer, thereby inhibiting induction of ambient air into said spaceduring purging thereof.

8. A method according to claim 7, wherein said container is round,further including initially forming said second stream in jet groupsalong an arcuate said line concentric with said container, including acentral group directed along parallel lines toward the mid-zone of saidspace and boundary groups at opposite sides of said central groupdirected along lines radially inward of said container toward segmentsof said space bordering said mid-zone, thereby efiecting consolidationof said second stream with said fourth stream, establishing asubstantially undivided principal stream flowing through said space, andinhibiting marginal flow beyond said space at the diametral line of saidcontainer crosswise of said principal stream.

9. A method according to claim 7, and establishing relative volume flowrates of said principal and third streams generally proportional to theratio of the undercover and under-lip spaces respectively swept thereby,thereby establishing generally the same velocities of said principal andthird streams in parallel above and below said lip respectively andsubstantially inhibiting cross-flow therebetween.

-10. A method according to claim 7, wherein said cover and container aremoved along converging paths to a location at which said cover issuperposed relative to said container, including initiating said firststream prior to superposition of said cover and prior to initiation ofthe other said streams, and thereafter maintaining said first stream atleast until superposition of said cover over said container andthroughout the flow period of the other said streams.

References Cited UNITED STATES PATENTS 2,692,715 10/1954 Doudera 53-110TRAVIS S. MCGEHEE, Primary Examiner US. Cl. X.R.

